Apparatus for concentrating sulfuric acid.



PATBNTBDDEU. 4. 190e.

. L. STANGIE.`

APPLIoAi'Iox rILnD lnPT.1a.1soe.

APPARATUS FOR GONGBNTRATING SULFURIG ACID Louis s'rANGn', or AIX-LA-c'nAr ELLE,

GERMANY.

APPARATUS FOR CONCENTRATING SULFU'RIC ACID.

Specification of Letters Patent.

Patented Dec. 4, 1906.

Application filed September 13, 1.906.` Serial No. 334,535.

To all, whom it may concern:

Be it known that I, Louis STANGE, a subject of the German Em eror, residing at Aixla-Chapelle, Germany, lieve 4invented certain new and useful Improvements in Apparatus for Concentrating Sulfuric Acid, of which the following is a specification.

This invention relatesto improvements in a paratus for concentrating sulfuric acid of t e t e in which the ,concentration is effecte in east-iron ans by blowing hot air over the surface and) by heating the pans.

According to this invention the cast-iron concentrating vessel'is provided with means for blowing heated air over the surface of the 4liquid in the vessel and with means for heatin the outside of the upper part of the vesse The vessel has a conduit near its lower end which communicates with a chamber beneath, and means are provided for cooling the chamber for the purpose of inerustations. An inner vessel o ening at, t e up er art of the containing vessel and is forme o acid-prooi` stoneware, the arrangement being such that the dilute acid passes down through the stoneware inner vessel and only) when concentrated passes into the s ace etween the inner stoneware vessel an the outer east-iron vessel. The lower chamber, which is cold and which reeeives the precipitate from the containiner vessel, is provided witha valve-controlled opening for the discharge of the precipitate t ierefrom.

The invention will be more particularly described with reference to the accompan f,- ing drawing, which represents in vertical sec tion one form of concentrating apparatus embodying this invention.

Vithin a brickwork foundation A is reventing raving an mounted a cast-iron pan B, of conical form,

having an outlet B at its lower end leading to a c amber C, connected with an outlettube D ior concentrated acid.

Contrary to the hitherto-known methods of concentrating sulfuric acid in cast-iron pans by heating Jfrom the bottom, the pan according to this invention is heated from the outside near the top` For this purpose a furnace E is provided with ilues F, which pass round the outside of the upper part of' the vessel B.. lAbove the furnace E are arranged air-heating pipes G, from which the hot air passes to an annular hot-air-distrib uting chamber its lower end is suspended within' H, surrounding the top of the containing vessel, ware From the chamber l'l a number of distributing-pipes J, (say six,) made of acidproof artificial stone, are directed onto the surface of the acid contained within thexessel B, and the main part of the concentration is eii'ected by the current of hot air thus produced over the surface of the acid.

' The frases escaping from the surface and containin dilute acid and watery vapor are conductec by a pipe K, passing through the lid B2, into a Glover tower or similar chamber L, where they serve to impart. a preliminary heating to. the dilute acid, which runs from the pan M at through the pipe vessel.

At the upper part of the concentrating vessel B -is arranged an inner vessel O, which corresponds in sha e with the outer vessel B and is construete of acid-proof stoneware. This vessel O is suspended-say by platinum connections-from the distributing-pipes J, whieh'eonvey the hot air to the surface of the acid contained within the vessel O.

' Surrounding the lower chamber C is a tank P, through which is circulated cooling-water to maintain the chamber C continuously cool. At the bottom of the chamber C is a coe through which the sludge from the bottom ot' the chamber C can pass into a sludge-receptacle B.

When the apparatus is first put into opera tion, the pan B is filled with strong acid near to the top, The air in the pipes G is heated by the furnace E, and by the action of the Glover tower o1' other chimney the air is sucked through t-he distributing-chamber H and the pipes .l and K. At the same time the hot gases from the furnace pass through the ilues F, surrounding the upper part of the vessel B, and assist in heating the contents. In the meantime the bottom chamber C is kept cool by circula ing cold water in the tank P. YVhen the acid on the top has reached its boiling-point, a certain quantity of dilute acid is allowed to run down into the inner vessel O through the pipe N from the pan M. This dilute acid reina'ning at the top of the inner vessel O displaees a correspendingquantity ol' thc concentrated acid in the chamber C through the overllow-pipc D. Heating of the acid at the top and cool ing at the bottom is continued until concentration is perfected, and the operation oi' lthe apparatus is then a continuous one.

N into the concentrating co'vered by a lid-of stonethe bottom of the tower L IOO ready concentrated.

f Hitherto it has been suggested to employ within a cast-iron concentrating-pan an `inner vessel of acid-resisting material standing upright on the bottom of the pan which was heated from the bottom but such an arrangement gave rise to the objection that the inner vessel was caused to jump by the action offthe heat, an effect which is avoided according to this invention by the arrangement of the inner vessel O, suspended at the upper part of the containing vessel B.

The effect of the arrangement constituting this invention is to produce a practically perfect continuity of the concentration. In all apparatus for concentrating sulfuric acid in cast-iron vessels a precipitate or .sludge consisting of ferrie sulfate is produced, and in vpans which are heated from the bottom this precipitate results in the formation of incrustations. According to this invention the sludge is kept in liquid state near the bottom of the chamber C on account of the cooling thereof, and the sludge of ferrie sulfate mixed with some concentrated acid can pass lthrough the cock Q when required into the sludge-receptacle R, and as the sludge is cold vthis method of removing it does not necessitate any interruption in the working of the apparatus, which has always been necessary inthe forms of cast-iron concentration apparatus hitherto used, which required to be repeatedly cleaned. As a result of the cooling of the acid at the bottom of the apparatus it is possible to construct the concentrating vessel B and the chamber C in two castings connected by a flange, so that the upper part B when eaten by the acid can be replaced, while the lower part C serves for a very long time. As only the acid to be concentrated is heated and as incrustations are rendered impossible, the result is a great saving of fuel.

`It is to be understood that the details of construction of the apparatus may be varied without departing from this invention.

.What I claim as my invention, and desire to secure by Letters Patent, is-

l. In an\ apparatus for concentrating sulfurie acid the combination of a liquid-containing vessel, a chamber communicating with its lower part, means for blowing heated gas over the surface of the liquid, means for heating the upper part of the containing Avessel externally and means for cooling said chamber.

2. In-'an apparatus for concentrating sulfuric acid the combination of a liquid-containing vessel, a chamber communicating `with its lower part, means for blowing heated its lower part, means for. blowing heated gas over the'surface ol' the li uid, means for heating the upper part of t e containing vessel externally, meanslor cooling said chamber and a valve-controlled o ening from the chamber for the dischargeo sludge therefrom.

4. In an apparatus for concentratin sulfurie acid the combination of a taining vessel, a chamber communicating with its lower part, means for blowing heated `gas over the surface of the liquid, means for heating the upper part of the containin@r vessel externally, means for cooling sai chamber, an inner vesselghav-ing..an-.opening at its lower end suspended withinthe'upper part. of said ,containing vessel and--a-valvecontrolled opening from the chamber for the discharge of sludgetherefrom.'

5. In anapparatus for concentrating sulfuric acid the combination of a cast-iron concentrating-pan having an outlet at the bottom, a chamber communicating with the outlet, a tank through which cooling-water is circulated surrounding said chamber, a furnace, heating-channels supplied with hot` gases from the furnace and surrouni lng theup er art of therpan, air-heatin ies above thfuionace, an annular hot-airgdisltributing conduit round the top of the pan connected to said air-heating pipes, and tubes leading from said annular conduit to direct hot air onto the liquid in the pan.

6. In an apparatus for concentrating sulfuric acid the combination of a cast-iron concentrating-pan having an outlet at the bot-r tom, a chamber communicating with the outlet, a tank throu h which cooling-water is circulated surround heating channels supplied' with hot gases from the furnace and surrounding the upper part of the. pan, air-heating pipesgabove the furnace, an. annular hot-airdistributing conduit round the top ofthe pan connected to said air-heatin pipes, tubes leading from said annular conduit to direct hot air onto the liquid in the pan and an inner vessel having an opening at its lower end constructed of acid-proof materialv corresponding in shape with the pan and suspended in the upper part of the pan.

7. In an, apparatus for concentrating sulfuric acid the combination o'f a cast-iron concentrating-pan having an outlet at the boting said chamber, a furnace,-

liqui -con- IOO IIO

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tom, a chamber communicating with the outlet, a tank through which cooling-Water is circulated surrounding said chamber, a furgases nace, heating-channels supplied With hot from the furnace 4and surrounding the upper part vof the pan, air-heating -pipes above the tributing conduitround the top of the pan connected to said air-heating pipes, tubes leading from said annular conduit to direct hot air onto the liquid in thepan, and an inner vessel having an opening at its lower end constructed .of acid-proof material corresponding in shape with the pan arid suspended in the upper part of the pan from the hot-air-distributing pipes.

8. In an apparatus for concentrating sulfuric acid the combination of a castfiron concentrating-pan having an outlet at the bottom, a chamber communicating with the outlet, a tank through which cooling-Water is circulated surrounding said chamber, a furnace, heatin -channels supplied with hot gases from the rnace and surrounding the upper part of the pan, air-heating pi es above the furnace, an annular hot-airistributing conduit round the top of the pan connected to said air-heating pipes, tubes leading from said annular conduit to direct hot air onto the liquid in the pan, an outlet from the cooled chamber, a cock in said outlet and a sludge-receptacle communicating with said outlet.

furnace, an annular hotair-dis' 9. In an apparatus for concentrating sulfuric acid the combination of a conical castiron concentrating-p an having an outlet at the bottom a chamber communicating with the outlet and forming a separate casting from the pan, a tank through which cooling-Water is circulated surrounding said chamber, a furnace, heating-channels supplied with hot gases from the furnace and surrounding) the upper part of the pan, air-heating ipes a ove nthe furnace, an annular hot-airistributing conduit round the top of the pan connected to said air-heatin pipes, tubesleading from said annular con ult to direct hot air onto the liquid in the pan, an inner vessel having an opening at its lower end constructed of acid-proof material, corres onding in shape with the pan and suspen 4ed in` the upper part of the pan from the hot-air-distributmg tubes, an outlet from the cooled chamber, a cock rin'said outlet and a sludge-receptacle communicating with said outlet.

In'testimony whereof I have signed my name to this specification'inthe presence of tWo subscribing Witnesses.

LOUIS STANGE.

Witnesses HENRY SHoETENsooK,

HERBERT BURRAGE. 

